/*-
 * SPDX-License-Identifier: BSD-4-Clause
 *
 * Copyright (c) 1980, 1989, 1993 The Regents of the University of California.
 * Copyright (c) 2000 Christoph Herrmann, Thomas-Henning von Kamptz
 * Copyright (c) 2012 The FreeBSD Foundation
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Christoph Herrmann and Thomas-Henning von Kamptz, Munich and Frankfurt.
 *
 * Portions of this software were developed by Edward Tomasz Napierala
 * under sponsorship from the FreeBSD Foundation.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgment:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors, as well as Christoph
 *      Herrmann and Thomas-Henning von Kamptz.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * $TSHeader: src/sbin/growfs/growfs.c,v 1.5 2000/12/12 19:31:00 tomsoft Exp $
 *
 */

#include <sys/param.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/disk.h>
#include <sys/ucred.h>
#include <sys/mount.h>

#include <stdio.h>
#include <paths.h>
#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <fstab.h>
#include <inttypes.h>
#include <limits.h>
#include <mntopts.h>
#include <paths.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <ufs/ufs/dinode.h>
#include <ufs/ffs/fs.h>
#include <libutil.h>
#include <libufs.h>

#include "debug.h"

#ifdef FS_DEBUG
int     _dbg_lvl_ = (DL_INFO);  /* DL_TRC */
#endif /* FS_DEBUG */

static union {
        struct fs       fs;
        char            pad[SBLOCKSIZE];
} fsun1, fsun2;
#define sblock  fsun1.fs        /* the new superblock */
#define osblock fsun2.fs        /* the old superblock */

static union {
        struct cg       cg;
        char            pad[MAXBSIZE];
} cgun1, cgun2;
#define acg     cgun1.cg        /* a cylinder cgroup (new) */
#define aocg    cgun2.cg        /* an old cylinder group */

static struct csum      *fscs;  /* cylinder summary */

static void     growfs(int, int, unsigned int);
static void     rdfs(ufs2_daddr_t, size_t, void *, int);
static void     wtfs(ufs2_daddr_t, size_t, void *, int, unsigned int);
static int      charsperline(void);
static void     usage(void);
static int      isblock(struct fs *, unsigned char *, int);
static void     clrblock(struct fs *, unsigned char *, int);
static void     setblock(struct fs *, unsigned char *, int);
static void     initcg(int, time_t, int, unsigned int);
static void     updjcg(int, time_t, int, int, unsigned int);
static void     updcsloc(time_t, int, int, unsigned int);
static void     frag_adjust(ufs2_daddr_t, int);
static void     updclst(int);
static void     cgckhash(struct cg *);

/*
 * Here we actually start growing the file system. We basically read the
 * cylinder summary from the first cylinder group as we want to update
 * this on the fly during our various operations. First we handle the
 * changes in the former last cylinder group. Afterwards we create all new
 * cylinder groups.  Now we handle the cylinder group containing the
 * cylinder summary which might result in a relocation of the whole
 * structure.  In the end we write back the updated cylinder summary, the
 * new superblock, and slightly patched versions of the super block
 * copies.
 */
static void
growfs(int fsi, int fso, unsigned int Nflag)
{
        DBG_FUNC("growfs")
        time_t modtime;
        uint cylno;
        int i, j, width;
        char tmpbuf[100];

        DBG_ENTER;

        time(&modtime);

        /*
         * Get the cylinder summary into the memory.
         */
        fscs = (struct csum *)calloc((size_t)1, (size_t)sblock.fs_cssize);
        if (fscs == NULL)
                errx(3, "calloc failed");
        memcpy(fscs, osblock.fs_csp, osblock.fs_cssize);
        free(osblock.fs_csp);
        osblock.fs_csp = NULL;
        sblock.fs_csp = fscs;

#ifdef FS_DEBUG
        {
                struct csum *dbg_csp;
                u_int32_t dbg_csc;
                char dbg_line[80];

                dbg_csp = fscs;

                for (dbg_csc = 0; dbg_csc < osblock.fs_ncg; dbg_csc++) {
                        snprintf(dbg_line, sizeof(dbg_line),
                            "%d. old csum in old location", dbg_csc);
                        DBG_DUMP_CSUM(&osblock, dbg_line, dbg_csp++);
                }
        }
#endif /* FS_DEBUG */
        DBG_PRINT0("fscs read\n");

        /*
         * Do all needed changes in the former last cylinder group.
         */
        updjcg(osblock.fs_ncg - 1, modtime, fsi, fso, Nflag);

        /*
         * Dump out summary information about file system.
         */
#ifdef FS_DEBUG
#define B2MBFACTOR (1 / (1024.0 * 1024.0))
        printf("growfs: %.1fMB (%jd sectors) block size %d, fragment size %d\n",
            (float)sblock.fs_size * sblock.fs_fsize * B2MBFACTOR,
            (intmax_t)fsbtodb(&sblock, sblock.fs_size), sblock.fs_bsize,
            sblock.fs_fsize);
        printf("\tusing %d cylinder groups of %.2fMB, %d blks, %d inodes.\n",
            sblock.fs_ncg, (float)sblock.fs_fpg * sblock.fs_fsize * B2MBFACTOR,
            sblock.fs_fpg / sblock.fs_frag, sblock.fs_ipg);
        if (sblock.fs_flags & FS_DOSOFTDEP)
                printf("\twith soft updates\n");
#undef B2MBFACTOR
#endif /* FS_DEBUG */

        /*
         * Now build the cylinders group blocks and
         * then print out indices of cylinder groups.
         */
        printf("super-block backups (for fsck_ffs -b #) at:\n");
        i = 0;
        width = charsperline();

        /*
         * Iterate for only the new cylinder groups.
         */
        for (cylno = osblock.fs_ncg; cylno < sblock.fs_ncg; cylno++) {
                initcg(cylno, modtime, fso, Nflag);
                j = sprintf(tmpbuf, " %jd%s",
                    (intmax_t)fsbtodb(&sblock, cgsblock(&sblock, cylno)),
                    cylno < (sblock.fs_ncg - 1) ? "," : "" );
                if (i + j >= width) {
                        printf("\n");
                        i = 0;
                }
                i += j;
                printf("%s", tmpbuf);
                fflush(stdout);
        }
        printf("\n");

        /*
         * Do all needed changes in the first cylinder group.
         * allocate blocks in new location
         */
        updcsloc(modtime, fsi, fso, Nflag);

        /*
         * Clean up the dynamic fields in our superblock.
         * 
         * XXX
         * The following fields are currently distributed from the superblock
         * to the copies:
         *     fs_minfree
         *     fs_rotdelay
         *     fs_maxcontig
         *     fs_maxbpg
         *     fs_minfree,
         *     fs_optim
         *     fs_flags
         *
         * We probably should rather change the summary for the cylinder group
         * statistics here to the value of what would be in there, if the file
         * system were created initially with the new size. Therefore we still
         * need to find an easy way of calculating that.
         * Possibly we can try to read the first superblock copy and apply the
         * "diffed" stats between the old and new superblock by still copying
         * certain parameters onto that.
         */
        sblock.fs_time = modtime;
        sblock.fs_fmod = 0;
        sblock.fs_clean = 1;
        sblock.fs_ronly = 0;
        sblock.fs_cgrotor = 0;
        sblock.fs_state = 0;
        memset((void *)&sblock.fs_fsmnt, 0, sizeof(sblock.fs_fsmnt));

        /*
         * Now write the new superblock, its summary information,
         * and all the alternates back to disk.
         */
        if (!Nflag && sbput(fso, &sblock, sblock.fs_ncg) != 0)
                errc(3, EIO, "could not write updated superblock");
        DBG_PRINT0("fscs written\n");

#ifdef FS_DEBUG
        {
                struct csum     *dbg_csp;
                u_int32_t       dbg_csc;
                char    dbg_line[80];

                dbg_csp = fscs;
                for (dbg_csc = 0; dbg_csc < sblock.fs_ncg; dbg_csc++) {
                        snprintf(dbg_line, sizeof(dbg_line),
                            "%d. new csum in new location", dbg_csc);
                        DBG_DUMP_CSUM(&sblock, dbg_line, dbg_csp++);
                }
        }
#endif /* FS_DEBUG */

        DBG_PRINT0("sblock written\n");
        DBG_DUMP_FS(&sblock, "new initial sblock");

        DBG_PRINT0("sblock copies written\n");
        DBG_DUMP_FS(&sblock, "new other sblocks");

        DBG_LEAVE;
        return;
}

/*
 * This creates a new cylinder group structure, for more details please see
 * the source of newfs(8), as this function is taken over almost unchanged.
 * As this is never called for the first cylinder group, the special
 * provisions for that case are removed here.
 */
static void
initcg(int cylno, time_t modtime, int fso, unsigned int Nflag)
{
        DBG_FUNC("initcg")
        static caddr_t iobuf;
        static long iobufsize;
        long blkno, start;
        ino_t ino;
        ufs2_daddr_t i, cbase, dmax;
        struct ufs1_dinode *dp1;
        struct ufs2_dinode *dp2;
        struct csum *cs;
        uint j, d, dupper, dlower;

        if (iobuf == NULL) {
                iobufsize = 2 * sblock.fs_bsize;
                if ((iobuf = malloc(iobufsize)) == NULL)
                        errx(37, "panic: cannot allocate I/O buffer");
                memset(iobuf, '\0', iobufsize);
        }
        /*
         * Determine block bounds for cylinder group.
         * Allow space for super block summary information in first
         * cylinder group.
         */
        cbase = cgbase(&sblock, cylno);
        dmax = cbase + sblock.fs_fpg;
        if (dmax > sblock.fs_size)
                dmax = sblock.fs_size;
        dlower = cgsblock(&sblock, cylno) - cbase;
        dupper = cgdmin(&sblock, cylno) - cbase;
        if (cylno == 0) /* XXX fscs may be relocated */
                dupper += howmany(sblock.fs_cssize, sblock.fs_fsize);
        cs = &fscs[cylno];
        memset(&acg, 0, sblock.fs_cgsize);
        acg.cg_time = modtime;
        acg.cg_magic = CG_MAGIC;
        acg.cg_cgx = cylno;
        acg.cg_niblk = sblock.fs_ipg;
        acg.cg_initediblk = MIN(sblock.fs_ipg, 2 * INOPB(&sblock));
        acg.cg_ndblk = dmax - cbase;
        if (sblock.fs_contigsumsize > 0)
                acg.cg_nclusterblks = acg.cg_ndblk / sblock.fs_frag;
        start = sizeof(acg);
        if (sblock.fs_magic == FS_UFS2_MAGIC) {
                acg.cg_iusedoff = start;
        } else {
                acg.cg_old_ncyl = sblock.fs_old_cpg;
                acg.cg_old_time = acg.cg_time;
                acg.cg_time = 0;
                acg.cg_old_niblk = acg.cg_niblk;
                acg.cg_niblk = 0;
                acg.cg_initediblk = 0;
                acg.cg_old_btotoff = start;
                acg.cg_old_boff = acg.cg_old_btotoff +
                    sblock.fs_old_cpg * sizeof(int32_t);
                acg.cg_iusedoff = acg.cg_old_boff +
                    sblock.fs_old_cpg * sizeof(u_int16_t);
        }
        acg.cg_freeoff = acg.cg_iusedoff + howmany(sblock.fs_ipg, CHAR_BIT);
        acg.cg_nextfreeoff = acg.cg_freeoff + howmany(sblock.fs_fpg, CHAR_BIT);
        if (sblock.fs_contigsumsize > 0) {
                acg.cg_clustersumoff =
                    roundup(acg.cg_nextfreeoff, sizeof(u_int32_t));
                acg.cg_clustersumoff -= sizeof(u_int32_t);
                acg.cg_clusteroff = acg.cg_clustersumoff +
                    (sblock.fs_contigsumsize + 1) * sizeof(u_int32_t);
                acg.cg_nextfreeoff = acg.cg_clusteroff +
                    howmany(fragstoblks(&sblock, sblock.fs_fpg), CHAR_BIT);
        }
        if (acg.cg_nextfreeoff > (unsigned)sblock.fs_cgsize) {
                /*
                 * This should never happen as we would have had that panic
                 * already on file system creation
                 */
                errx(37, "panic: cylinder group too big");
        }
        acg.cg_cs.cs_nifree += sblock.fs_ipg;
        if (cylno == 0)
                for (ino = 0; ino < UFS_ROOTINO; ino++) {
                        setbit(cg_inosused(&acg), ino);
                        acg.cg_cs.cs_nifree--;
                }
        /*
         * Initialize the initial inode blocks.
         */
        dp1 = (struct ufs1_dinode *)(void *)iobuf;
        dp2 = (struct ufs2_dinode *)(void *)iobuf;
        for (i = 0; i < acg.cg_initediblk; i++) {
                if (sblock.fs_magic == FS_UFS1_MAGIC) {
                        dp1->di_gen = arc4random();
                        dp1++;
                } else {
                        dp2->di_gen = arc4random();
                        dp2++;
                }
        }
        wtfs(fsbtodb(&sblock, cgimin(&sblock, cylno)), iobufsize, iobuf,
            fso, Nflag);
        /*
         * For the old file system, we have to initialize all the inodes.
         */
        if (sblock.fs_magic == FS_UFS1_MAGIC &&
            sblock.fs_ipg > 2 * INOPB(&sblock)) {
                for (i = 2 * sblock.fs_frag;
                     i < sblock.fs_ipg / INOPF(&sblock);
                     i += sblock.fs_frag) {
                        dp1 = (struct ufs1_dinode *)(void *)iobuf;
                        for (j = 0; j < INOPB(&sblock); j++) {
                                dp1->di_gen = arc4random();
                                dp1++;
                        }
                        wtfs(fsbtodb(&sblock, cgimin(&sblock, cylno) + i),
                            sblock.fs_bsize, iobuf, fso, Nflag);
                }
        }
        if (cylno > 0) {
                /*
                 * In cylno 0, beginning space is reserved
                 * for boot and super blocks.
                 */
                for (d = 0; d < dlower; d += sblock.fs_frag) {
                        blkno = d / sblock.fs_frag;
                        setblock(&sblock, cg_blksfree(&acg), blkno);
                        if (sblock.fs_contigsumsize > 0)
                                setbit(cg_clustersfree(&acg), blkno);
                        acg.cg_cs.cs_nbfree++;
                }
                sblock.fs_dsize += dlower;
        }
        sblock.fs_dsize += acg.cg_ndblk - dupper;
        sblock.fs_old_dsize = sblock.fs_dsize;
        if ((i = dupper % sblock.fs_frag)) {
                acg.cg_frsum[sblock.fs_frag - i]++;
                for (d = dupper + sblock.fs_frag - i; dupper < d; dupper++) {
                        setbit(cg_blksfree(&acg), dupper);
                        acg.cg_cs.cs_nffree++;
                }
        }
        for (d = dupper; d + sblock.fs_frag <= acg.cg_ndblk;
            d += sblock.fs_frag) {
                blkno = d / sblock.fs_frag;
                setblock(&sblock, cg_blksfree(&acg), blkno);
                if (sblock.fs_contigsumsize > 0)
                        setbit(cg_clustersfree(&acg), blkno);
                acg.cg_cs.cs_nbfree++;
        }
        if (d < acg.cg_ndblk) {
                acg.cg_frsum[acg.cg_ndblk - d]++;
                for (; d < acg.cg_ndblk; d++) {
                        setbit(cg_blksfree(&acg), d);
                        acg.cg_cs.cs_nffree++;
                }
        }
        if (sblock.fs_contigsumsize > 0) {
                int32_t *sump = cg_clustersum(&acg);
                u_char *mapp = cg_clustersfree(&acg);
                int map = *mapp++;
                int bit = 1;
                int run = 0;

                for (i = 0; i < acg.cg_nclusterblks; i++) {
                        if ((map & bit) != 0)
                                run++;
                        else if (run != 0) {
                                if (run > sblock.fs_contigsumsize)
                                        run = sblock.fs_contigsumsize;
                                sump[run]++;
                                run = 0;
                        }
                        if ((i & (CHAR_BIT - 1)) != CHAR_BIT - 1)
                                bit <<= 1;
                        else {
                                map = *mapp++;
                                bit = 1;
                        }
                }
                if (run != 0) {
                        if (run > sblock.fs_contigsumsize)
                                run = sblock.fs_contigsumsize;
                        sump[run]++;
                }
        }
        sblock.fs_cstotal.cs_ndir += acg.cg_cs.cs_ndir;
        sblock.fs_cstotal.cs_nffree += acg.cg_cs.cs_nffree;
        sblock.fs_cstotal.cs_nbfree += acg.cg_cs.cs_nbfree;
        sblock.fs_cstotal.cs_nifree += acg.cg_cs.cs_nifree;
        *cs = acg.cg_cs;

        cgckhash(&acg);
        wtfs(fsbtodb(&sblock, cgtod(&sblock, cylno)), sblock.fs_cgsize, &acg,
            fso, Nflag);
        DBG_DUMP_CG(&sblock, "new cg", &acg);

        DBG_LEAVE;
        return;
}

/*
 * Here we add or subtract (sign +1/-1) the available fragments in a given
 * block to or from the fragment statistics. By subtracting before and adding
 * after an operation on the free frag map we can easy update the fragment
 * statistic, which seems to be otherwise a rather complex operation.
 */
static void
frag_adjust(ufs2_daddr_t frag, int sign)
{
        DBG_FUNC("frag_adjust")
        int fragsize;
        int f;

        DBG_ENTER;

        fragsize = 0;
        /*
         * Here frag only needs to point to any fragment in the block we want
         * to examine.
         */
        for (f = rounddown(frag, sblock.fs_frag);
            f < roundup(frag + 1, sblock.fs_frag); f++) {
                /*
                 * Count contiguous free fragments.
                 */
                if (isset(cg_blksfree(&acg), f)) {
                        fragsize++;
                } else {
                        if (fragsize && fragsize < sblock.fs_frag) {
                                /*
                                 * We found something in between.
                                 */
                                acg.cg_frsum[fragsize] += sign;
                                DBG_PRINT2("frag_adjust [%d]+=%d\n",
                                    fragsize, sign);
                        }
                        fragsize = 0;
                }
        }
        if (fragsize && fragsize < sblock.fs_frag) {
                /*
                 * We found something.
                 */
                acg.cg_frsum[fragsize] += sign;
                DBG_PRINT2("frag_adjust [%d]+=%d\n", fragsize, sign);
        }
        DBG_PRINT2("frag_adjust [[%d]]+=%d\n", fragsize, sign);

        DBG_LEAVE;
        return;
}

/*
 * Here we do all needed work for the former last cylinder group. It has to be
 * changed in any case, even if the file system ended exactly on the end of
 * this group, as there is some slightly inconsistent handling of the number
 * of cylinders in the cylinder group. We start again by reading the cylinder
 * group from disk. If the last block was not fully available, we first handle
 * the missing fragments, then we handle all new full blocks in that file
 * system and finally we handle the new last fragmented block in the file
 * system.  We again have to handle the fragment statistics rotational layout
 * tables and cluster summary during all those operations.
 */
static void
updjcg(int cylno, time_t modtime, int fsi, int fso, unsigned int Nflag)
{
        DBG_FUNC("updjcg")
        ufs2_daddr_t cbase, dmax;
        struct csum *cs;
        int i, k;
        int j = 0;

        DBG_ENTER;

        /*
         * Read the former last (joining) cylinder group from disk, and make
         * a copy.
         */
        rdfs(fsbtodb(&osblock, cgtod(&osblock, cylno)),
            (size_t)osblock.fs_cgsize, (void *)&aocg, fsi);
        DBG_PRINT0("jcg read\n");
        DBG_DUMP_CG(&sblock, "old joining cg", &aocg);

        memcpy((void *)&cgun1, (void *)&cgun2, sizeof(cgun2));

        /*
         * If the cylinder group had already its new final size almost
         * nothing is to be done ... except:
         * For some reason the value of cg_ncyl in the last cylinder group has
         * to be zero instead of fs_cpg. As this is now no longer the last
         * cylinder group we have to change that value now to fs_cpg.
         */

        if (cgbase(&osblock, cylno + 1) == osblock.fs_size) {
                if (sblock.fs_magic == FS_UFS1_MAGIC)
                        acg.cg_old_ncyl = sblock.fs_old_cpg;

                cgckhash(&acg);
                wtfs(fsbtodb(&sblock, cgtod(&sblock, cylno)),
                    (size_t)sblock.fs_cgsize, (void *)&acg, fso, Nflag);
                DBG_PRINT0("jcg written\n");
                DBG_DUMP_CG(&sblock, "new joining cg", &acg);

                DBG_LEAVE;
                return;
        }

        /*
         * Set up some variables needed later.
         */
        cbase = cgbase(&sblock, cylno);
        dmax = cbase + sblock.fs_fpg;
        if (dmax > sblock.fs_size)
                dmax = sblock.fs_size;

        /*
         * Set pointer to the cylinder summary for our cylinder group.
         */
        cs = fscs + cylno;

        /*
         * Touch the cylinder group, update all fields in the cylinder group as
         * needed, update the free space in the superblock.
         */
        acg.cg_time = modtime;
        if ((unsigned)cylno == sblock.fs_ncg - 1) {
                /*
                 * This is still the last cylinder group.
                 */
                if (sblock.fs_magic == FS_UFS1_MAGIC)
                        acg.cg_old_ncyl =
                            sblock.fs_old_ncyl % sblock.fs_old_cpg;
        } else {
                acg.cg_old_ncyl = sblock.fs_old_cpg;
        }
        DBG_PRINT2("jcg dbg: %d %u", cylno, sblock.fs_ncg);
#ifdef FS_DEBUG
        if (sblock.fs_magic == FS_UFS1_MAGIC)
                DBG_PRINT2("%d %u", acg.cg_old_ncyl, sblock.fs_old_cpg);
#endif
        DBG_PRINT0("\n");
        acg.cg_ndblk = dmax - cbase;
        sblock.fs_dsize += acg.cg_ndblk - aocg.cg_ndblk;
        sblock.fs_old_dsize = sblock.fs_dsize;
        if (sblock.fs_contigsumsize > 0)
                acg.cg_nclusterblks = acg.cg_ndblk / sblock.fs_frag;

        /*
         * Now we have to update the free fragment bitmap for our new free
         * space.  There again we have to handle the fragmentation and also
         * the rotational layout tables and the cluster summary.  This is
         * also done per fragment for the first new block if the old file
         * system end was not on a block boundary, per fragment for the new
         * last block if the new file system end is not on a block boundary,
         * and per block for all space in between.
         *
         * Handle the first new block here if it was partially available
         * before.
         */
        if (osblock.fs_size % sblock.fs_frag) {
                if (roundup(osblock.fs_size, sblock.fs_frag) <=
                    sblock.fs_size) {
                        /*
                         * The new space is enough to fill at least this
                         * block
                         */
                        j = 0;
                        for (i = roundup(osblock.fs_size - cbase,
                            sblock.fs_frag) - 1; i >= osblock.fs_size - cbase;
                            i--) {
                                setbit(cg_blksfree(&acg), i);
                                acg.cg_cs.cs_nffree++;
                                j++;
                        }

                        /*
                         * Check if the fragment just created could join an
                         * already existing fragment at the former end of the
                         * file system.
                         */
                        if (isblock(&sblock, cg_blksfree(&acg),
                            ((osblock.fs_size - cgbase(&sblock, cylno)) /
                             sblock.fs_frag))) {
                                /*
                                 * The block is now completely available.
                                 */
                                DBG_PRINT0("block was\n");
                                acg.cg_frsum[osblock.fs_size % sblock.fs_frag]--;
                                acg.cg_cs.cs_nbfree++;
                                acg.cg_cs.cs_nffree -= sblock.fs_frag;
                                k = rounddown(osblock.fs_size - cbase,
                                    sblock.fs_frag);
                                updclst((osblock.fs_size - cbase) /
                                    sblock.fs_frag);
                        } else {
                                /*
                                 * Lets rejoin a possible partially grown
                                 * fragment.
                                 */
                                k = 0;
                                while (isset(cg_blksfree(&acg), i) &&
                                    (i >= rounddown(osblock.fs_size - cbase,
                                    sblock.fs_frag))) {
                                        i--;
                                        k++;
                                }
                                if (k)
                                        acg.cg_frsum[k]--;
                                acg.cg_frsum[k + j]++;
                        }
                } else {
                        /*
                         * We only grow by some fragments within this last
                         * block.
                         */
                        for (i = sblock.fs_size - cbase - 1;
                            i >= osblock.fs_size - cbase; i--) {
                                setbit(cg_blksfree(&acg), i);
                                acg.cg_cs.cs_nffree++;
                                j++;
                        }
                        /*
                         * Lets rejoin a possible partially grown fragment.
                         */
                        k = 0;
                        while (isset(cg_blksfree(&acg), i) &&
                            (i >= rounddown(osblock.fs_size - cbase,
                            sblock.fs_frag))) {
                                i--;
                                k++;
                        }
                        if (k)
                                acg.cg_frsum[k]--;
                        acg.cg_frsum[k + j]++;
                }
        }

        /*
         * Handle all new complete blocks here.
         */
        for (i = roundup(osblock.fs_size - cbase, sblock.fs_frag);
            i + sblock.fs_frag <= dmax - cbase; /* XXX <= or only < ? */
            i += sblock.fs_frag) {
                j = i / sblock.fs_frag;
                setblock(&sblock, cg_blksfree(&acg), j);
                updclst(j);
                acg.cg_cs.cs_nbfree++;
        }

        /*
         * Handle the last new block if there are still some new fragments left.
         * Here we don't have to bother about the cluster summary or the even
         * the rotational layout table.
         */
        if (i < (dmax - cbase)) {
                acg.cg_frsum[dmax - cbase - i]++;
                for (; i < dmax - cbase; i++) {
                        setbit(cg_blksfree(&acg), i);
                        acg.cg_cs.cs_nffree++;
                }
        }

        sblock.fs_cstotal.cs_nffree +=
            (acg.cg_cs.cs_nffree - aocg.cg_cs.cs_nffree);
        sblock.fs_cstotal.cs_nbfree +=
            (acg.cg_cs.cs_nbfree - aocg.cg_cs.cs_nbfree);
        /*
         * The following statistics are not changed here:
         *     sblock.fs_cstotal.cs_ndir
         *     sblock.fs_cstotal.cs_nifree
         * As the statistics for this cylinder group are ready, copy it to
         * the summary information array.
         */
        *cs = acg.cg_cs;

        /*
         * Write the updated "joining" cylinder group back to disk.
         */
        cgckhash(&acg);
        wtfs(fsbtodb(&sblock, cgtod(&sblock, cylno)), (size_t)sblock.fs_cgsize,
            (void *)&acg, fso, Nflag);
        DBG_PRINT0("jcg written\n");
        DBG_DUMP_CG(&sblock, "new joining cg", &acg);

        DBG_LEAVE;
        return;
}

/*
 * Here we update the location of the cylinder summary. We have two possible
 * ways of growing the cylinder summary:
 * (1)  We can try to grow the summary in the current location, and relocate
 *      possibly used blocks within the current cylinder group.
 * (2)  Alternatively we can relocate the whole cylinder summary to the first
 *      new completely empty cylinder group. Once the cylinder summary is no
 *      longer in the beginning of the first cylinder group you should never
 *      use a version of fsck which is not aware of the possibility to have
 *      this structure in a non standard place.
 * Option (2) is considered to be less intrusive to the structure of the file-
 * system, so that's the one being used.
 */
static void
updcsloc(time_t modtime, int fsi, int fso, unsigned int Nflag)
{
        DBG_FUNC("updcsloc")
        struct csum *cs;
        int ocscg, ncscg;
        ufs2_daddr_t d;
        int lcs = 0;
        int block;

        DBG_ENTER;

        if (howmany(sblock.fs_cssize, sblock.fs_fsize) ==
            howmany(osblock.fs_cssize, osblock.fs_fsize)) {
                /*
                 * No new fragment needed.
                 */
                DBG_LEAVE;
                return;
        }
        /* Adjust fs_dsize by added summary blocks */
        sblock.fs_dsize -= howmany(sblock.fs_cssize, sblock.fs_fsize) -
            howmany(osblock.fs_cssize, osblock.fs_fsize);
        sblock.fs_old_dsize = sblock.fs_dsize;
        ocscg = dtog(&osblock, osblock.fs_csaddr);
        cs = fscs + ocscg;

        /*
         * Read original cylinder group from disk, and make a copy.
         * XXX  If Nflag is set in some very rare cases we now miss
         *      some changes done in updjcg by reading the unmodified
         *      block from disk.
         */
        rdfs(fsbtodb(&osblock, cgtod(&osblock, ocscg)),
            (size_t)osblock.fs_cgsize, (void *)&aocg, fsi);
        DBG_PRINT0("oscg read\n");
        DBG_DUMP_CG(&sblock, "old summary cg", &aocg);

        memcpy((void *)&cgun1, (void *)&cgun2, sizeof(cgun2));

        /*
         * Touch the cylinder group, set up local variables needed later
         * and update the superblock.
         */
        acg.cg_time = modtime;

        /*
         * XXX  In the case of having active snapshots we may need much more
         *      blocks for the copy on write. We need each block twice, and
         *      also up to 8*3 blocks for indirect blocks for all possible
         *      references.
         */
        /*
         * There is not enough space in the old cylinder group to
         * relocate all blocks as needed, so we relocate the whole
         * cylinder group summary to a new group. We try to use the
         * first complete new cylinder group just created. Within the
         * cylinder group we align the area immediately after the
         * cylinder group information location in order to be as
         * close as possible to the original implementation of ffs.
         *
         * First we have to make sure we'll find enough space in the
         * new cylinder group. If not, then we currently give up.
         * We start with freeing everything which was used by the
         * fragments of the old cylinder summary in the current group.
         * Now we write back the group meta data, read in the needed
         * meta data from the new cylinder group, and start allocating
         * within that group. Here we can assume, the group to be
         * completely empty. Which makes the handling of fragments and
         * clusters a lot easier.
         */
        DBG_TRC;
        if (sblock.fs_ncg - osblock.fs_ncg < 2)
                errx(2, "panic: not enough space");

        /*
         * Point "d" to the first fragment not used by the cylinder
         * summary.
         */
        d = osblock.fs_csaddr + (osblock.fs_cssize / osblock.fs_fsize);

        /*
         * Set up last cluster size ("lcs") already here. Calculate
         * the size for the trailing cluster just behind where "d"
         * points to.
         */
        if (sblock.fs_contigsumsize > 0) {
                for (block = howmany(d % sblock.fs_fpg, sblock.fs_frag),
                    lcs = 0; lcs < sblock.fs_contigsumsize; block++, lcs++) {
                        if (isclr(cg_clustersfree(&acg), block))
                                break;
                }
        }

        /*
         * Point "d" to the last frag used by the cylinder summary.
         */
        d--;

        DBG_PRINT1("d=%jd\n", (intmax_t)d);
        if ((d + 1) % sblock.fs_frag) {
                /*
                 * The end of the cylinder summary is not a complete
                 * block.
                 */
                DBG_TRC;
                frag_adjust(d % sblock.fs_fpg, -1);
                for (; (d + 1) % sblock.fs_frag; d--) {
                        DBG_PRINT1("d=%jd\n", (intmax_t)d);
                        setbit(cg_blksfree(&acg), d % sblock.fs_fpg);
                        acg.cg_cs.cs_nffree++;
                        sblock.fs_cstotal.cs_nffree++;
                }
                /*
                 * Point "d" to the last fragment of the last
                 * (incomplete) block of the cylinder summary.
                 */
                d++;
                frag_adjust(d % sblock.fs_fpg, 1);

                if (isblock(&sblock, cg_blksfree(&acg),
                    (d % sblock.fs_fpg) / sblock.fs_frag)) {
                        DBG_PRINT1("d=%jd\n", (intmax_t)d);
                        acg.cg_cs.cs_nffree -= sblock.fs_frag;
                        acg.cg_cs.cs_nbfree++;
                        sblock.fs_cstotal.cs_nffree -= sblock.fs_frag;
                        sblock.fs_cstotal.cs_nbfree++;
                        if (sblock.fs_contigsumsize > 0) {
                                setbit(cg_clustersfree(&acg),
                                    (d % sblock.fs_fpg) / sblock.fs_frag);
                                if (lcs < sblock.fs_contigsumsize) {
                                        if (lcs)
                                                cg_clustersum(&acg)[lcs]--;
                                        lcs++;
                                        cg_clustersum(&acg)[lcs]++;
                                }
                        }
                }
                /*
                 * Point "d" to the first fragment of the block before
                 * the last incomplete block.
                 */
                d--;
        }

        DBG_PRINT1("d=%jd\n", (intmax_t)d);
        for (d = rounddown(d, sblock.fs_frag); d >= osblock.fs_csaddr;
            d -= sblock.fs_frag) {
                DBG_TRC;
                DBG_PRINT1("d=%jd\n", (intmax_t)d);
                setblock(&sblock, cg_blksfree(&acg),
                    (d % sblock.fs_fpg) / sblock.fs_frag);
                acg.cg_cs.cs_nbfree++;
                sblock.fs_cstotal.cs_nbfree++;
                if (sblock.fs_contigsumsize > 0) {
                        setbit(cg_clustersfree(&acg),
                            (d % sblock.fs_fpg) / sblock.fs_frag);
                        /*
                         * The last cluster size is already set up.
                         */
                        if (lcs < sblock.fs_contigsumsize) {
                                if (lcs)
                                        cg_clustersum(&acg)[lcs]--;
                                lcs++;
                                cg_clustersum(&acg)[lcs]++;
                        }
                }
        }
        *cs = acg.cg_cs;

        /*
         * Now write the former cylinder group containing the cylinder
         * summary back to disk.
         */
        cgckhash(&acg);
        wtfs(fsbtodb(&sblock, cgtod(&sblock, ocscg)),
            (size_t)sblock.fs_cgsize, (void *)&acg, fso, Nflag);
        DBG_PRINT0("oscg written\n");
        DBG_DUMP_CG(&sblock, "old summary cg", &acg);

        /*
         * Find the beginning of the new cylinder group containing the
         * cylinder summary.
         */
        sblock.fs_csaddr = cgdmin(&sblock, osblock.fs_ncg);
        ncscg = dtog(&sblock, sblock.fs_csaddr);
        cs = fscs + ncscg;

        /*
         * If Nflag is specified, we would now read random data instead
         * of an empty cg structure from disk. So we can't simulate that
         * part for now.
         */
        if (Nflag) {
                DBG_PRINT0("nscg update skipped\n");
                DBG_LEAVE;
                return;
        }

        /*
         * Read the future cylinder group containing the cylinder
         * summary from disk, and make a copy.
         */
        rdfs(fsbtodb(&sblock, cgtod(&sblock, ncscg)),
            (size_t)sblock.fs_cgsize, (void *)&aocg, fsi);
        DBG_PRINT0("nscg read\n");
        DBG_DUMP_CG(&sblock, "new summary cg", &aocg);

        memcpy((void *)&cgun1, (void *)&cgun2, sizeof(cgun2));

        /*
         * Allocate all complete blocks used by the new cylinder
         * summary.
         */
        for (d = sblock.fs_csaddr; d + sblock.fs_frag <=
            sblock.fs_csaddr + (sblock.fs_cssize / sblock.fs_fsize);
            d += sblock.fs_frag) {
                clrblock(&sblock, cg_blksfree(&acg),
                    (d % sblock.fs_fpg) / sblock.fs_frag);
                acg.cg_cs.cs_nbfree--;
                sblock.fs_cstotal.cs_nbfree--;
                if (sblock.fs_contigsumsize > 0) {
                        clrbit(cg_clustersfree(&acg),
                            (d % sblock.fs_fpg) / sblock.fs_frag);
                }
        }

        /*
         * Allocate all fragments used by the cylinder summary in the
         * last block.
         */
        if (d < sblock.fs_csaddr + (sblock.fs_cssize / sblock.fs_fsize)) {
                for (; d - sblock.fs_csaddr <
                    sblock.fs_cssize/sblock.fs_fsize; d++) {
                        clrbit(cg_blksfree(&acg), d % sblock.fs_fpg);
                        acg.cg_cs.cs_nffree--;
                        sblock.fs_cstotal.cs_nffree--;
                }
                acg.cg_cs.cs_nbfree--;
                acg.cg_cs.cs_nffree += sblock.fs_frag;
                sblock.fs_cstotal.cs_nbfree--;
                sblock.fs_cstotal.cs_nffree += sblock.fs_frag;
                if (sblock.fs_contigsumsize > 0)
                        clrbit(cg_clustersfree(&acg),
                            (d % sblock.fs_fpg) / sblock.fs_frag);

                frag_adjust(d % sblock.fs_fpg, 1);
        }
        /*
         * XXX  Handle the cluster statistics here in the case this
         *      cylinder group is now almost full, and the remaining
         *      space is less then the maximum cluster size. This is
         *      probably not needed, as you would hardly find a file
         *      system which has only MAXCSBUFS+FS_MAXCONTIG of free
         *      space right behind the cylinder group information in
         *      any new cylinder group.
         */

        /*
         * Update our statistics in the cylinder summary.
         */
        *cs = acg.cg_cs;

        /*
         * Write the new cylinder group containing the cylinder summary
         * back to disk.
         */
        cgckhash(&acg);
        wtfs(fsbtodb(&sblock, cgtod(&sblock, ncscg)),
            (size_t)sblock.fs_cgsize, (void *)&acg, fso, Nflag);
        DBG_PRINT0("nscg written\n");
        DBG_DUMP_CG(&sblock, "new summary cg", &acg);

        DBG_LEAVE;
        return;
}

/*
 * Here we read some block(s) from disk.
 */
static void
rdfs(ufs2_daddr_t bno, size_t size, void *bf, int fsi)
{
        DBG_FUNC("rdfs")
        ssize_t n;

        DBG_ENTER;

        if (bno < 0)
                err(32, "rdfs: attempting to read negative block number");
        if (lseek(fsi, (off_t)bno * DEV_BSIZE, 0) < 0)
                err(33, "rdfs: seek error: %jd", (intmax_t)bno);
        n = read(fsi, bf, size);
        if (n != (ssize_t)size)
                err(34, "rdfs: read error: %jd", (intmax_t)bno);

        DBG_LEAVE;
        return;
}

/*
 * Here we write some block(s) to disk.
 */
static void
wtfs(ufs2_daddr_t bno, size_t size, void *bf, int fso, unsigned int Nflag)
{
        DBG_FUNC("wtfs")
        ssize_t n;

        DBG_ENTER;

        if (Nflag) {
                DBG_LEAVE;
                return;
        }
        if (lseek(fso, (off_t)bno * DEV_BSIZE, SEEK_SET) < 0)
                err(35, "wtfs: seek error: %ld", (long)bno);
        n = write(fso, bf, size);
        if (n != (ssize_t)size)
                err(36, "wtfs: write error: %ld", (long)bno);

        DBG_LEAVE;
        return;
}

/*
 * Here we check if all frags of a block are free. For more details again
 * please see the source of newfs(8), as this function is taken over almost
 * unchanged.
 */
static int
isblock(struct fs *fs, unsigned char *cp, int h)
{
        DBG_FUNC("isblock")
        unsigned char mask;

        DBG_ENTER;

        switch (fs->fs_frag) {
        case 8:
                DBG_LEAVE;
                return (cp[h] == 0xff);
        case 4:
                mask = 0x0f << ((h & 0x1) << 2);
                DBG_LEAVE;
                return ((cp[h >> 1] & mask) == mask);
        case 2:
                mask = 0x03 << ((h & 0x3) << 1);
                DBG_LEAVE;
                return ((cp[h >> 2] & mask) == mask);
        case 1:
                mask = 0x01 << (h & 0x7);
                DBG_LEAVE;
                return ((cp[h >> 3] & mask) == mask);
        default:
                fprintf(stderr, "isblock bad fs_frag %d\n", fs->fs_frag);
                DBG_LEAVE;
                return (0);
        }
}

/*
 * Here we allocate a complete block in the block map. For more details again
 * please see the source of newfs(8), as this function is taken over almost
 * unchanged.
 */
static void
clrblock(struct fs *fs, unsigned char *cp, int h)
{
        DBG_FUNC("clrblock")

        DBG_ENTER;

        switch ((fs)->fs_frag) {
        case 8:
                cp[h] = 0;
                break;
        case 4:
                cp[h >> 1] &= ~(0x0f << ((h & 0x1) << 2));
                break;
        case 2:
                cp[h >> 2] &= ~(0x03 << ((h & 0x3) << 1));
                break;
        case 1:
                cp[h >> 3] &= ~(0x01 << (h & 0x7));
                break;
        default:
                warnx("clrblock bad fs_frag %d", fs->fs_frag);
                break;
        }

        DBG_LEAVE;
        return;
}

/*
 * Here we free a complete block in the free block map. For more details again
 * please see the source of newfs(8), as this function is taken over almost
 * unchanged.
 */
static void
setblock(struct fs *fs, unsigned char *cp, int h)
{
        DBG_FUNC("setblock")

        DBG_ENTER;

        switch (fs->fs_frag) {
        case 8:
                cp[h] = 0xff;
                break;
        case 4:
                cp[h >> 1] |= (0x0f << ((h & 0x1) << 2));
                break;
        case 2:
                cp[h >> 2] |= (0x03 << ((h & 0x3) << 1));
                break;
        case 1:
                cp[h >> 3] |= (0x01 << (h & 0x7));
                break;
        default:
                warnx("setblock bad fs_frag %d", fs->fs_frag);
                break;
        }

        DBG_LEAVE;
        return;
}

/*
 * Figure out how many lines our current terminal has. For more details again
 * please see the source of newfs(8), as this function is taken over almost
 * unchanged.
 */
static int
charsperline(void)
{
        DBG_FUNC("charsperline")
        int columns;
        char *cp;
        struct winsize ws;

        DBG_ENTER;

        columns = 0;
        if (ioctl(0, TIOCGWINSZ, &ws) != -1)
                columns = ws.ws_col;
        if (columns == 0 && (cp = getenv("COLUMNS")))
                columns = atoi(cp);
        if (columns == 0)
                columns = 80;   /* last resort */

        DBG_LEAVE;
        return (columns);
}

static int
is_dev(const char *name)
{
        struct stat devstat;

        if (stat(name, &devstat) != 0)
                return (0);
        if (!S_ISCHR(devstat.st_mode))
                return (0);
        return (1);
}

static const char *
getdev(const char *name, struct statfs *statfsp)
{
        static char device[MAXPATHLEN];
        const char *cp;

        if (is_dev(name))
                return (name);

        cp = strrchr(name, '/');
        if (cp == NULL) {
                snprintf(device, sizeof(device), "%s%s", _PATH_DEV, name);
                if (is_dev(device))
                        return (device);
        }

        if (statfsp != NULL)
                return (statfsp->f_mntfromname);

        return (NULL);
}

/*
 * growfs(8) is a utility which allows to increase the size of an existing
 * ufs file system. Currently this can only be done on unmounted file system.
 * It recognizes some command line options to specify the new desired size,
 * and it does some basic checkings. The old file system size is determined
 * and after some more checks like we can really access the new last block
 * on the disk etc. we calculate the new parameters for the superblock. After
 * having done this we just call growfs() which will do the work.
 * We still have to provide support for snapshots. Therefore we first have to
 * understand what data structures are always replicated in the snapshot on
 * creation, for all other blocks we touch during our procedure, we have to
 * keep the old blocks unchanged somewhere available for the snapshots. If we
 * are lucky, then we only have to handle our blocks to be relocated in that
 * way.
 * Also we have to consider in what order we actually update the critical
 * data structures of the file system to make sure, that in case of a disaster
 * fsck(8) is still able to restore any lost data.
 * The foreseen last step then will be to provide for growing even mounted
 * file systems. There we have to extend the mount() system call to provide
 * userland access to the file system locking facility.
 */
int
main(int argc, char **argv)
{
        DBG_FUNC("main")
        struct fs *fs;
        const char *device;
        struct statfs *statfsp;
        uint64_t size = 0;
        off_t mediasize;
        int error, j, fsi, fso, ch, ret, Nflag = 0, yflag = 0;
        char *p, reply[5], oldsizebuf[6], newsizebuf[6];
        void *testbuf;

        DBG_ENTER;

        while ((ch = getopt(argc, argv, "Ns:vy")) != -1) {
                switch(ch) {
                case 'N':
                        Nflag = 1;
                        break;
                case 's':
                        size = (off_t)strtoumax(optarg, &p, 0);
                        if (p == NULL || *p == '\0')
                                size *= DEV_BSIZE;
                        else if (*p == 'b' || *p == 'B')
                                ; /* do nothing */
                        else if (*p == 'k' || *p == 'K')
                                size <<= 10;
                        else if (*p == 'm' || *p == 'M')
                                size <<= 20;
                        else if (*p == 'g' || *p == 'G')
                                size <<= 30;
                        else if (*p == 't' || *p == 'T') {
                                size <<= 30;
                                size <<= 10;
                        } else
                                errx(2, "unknown suffix on -s argument");
                        break;
                case 'v': /* for compatibility to newfs */
                        break;
                case 'y':
                        yflag = 1;
                        break;
                case '?':
                        /* FALLTHROUGH */
                default:
                        usage();
                }
        }
        argc -= optind;
        argv += optind;

        if (argc != 1)
                usage();

        /*
         * Now try to guess the device name.
         */
        statfsp = getmntpoint(*argv);
        device = getdev(*argv, statfsp);
        if (device == NULL)
                errx(2, "cannot find special device for %s", *argv);

        fsi = open(device, O_RDONLY);
        if (fsi < 0)
                err(3, "%s", device);

        /*
         * Try to guess the slice size if not specified.
         */
        if (ioctl(fsi, DIOCGMEDIASIZE, &mediasize) == -1)
                err(3,"DIOCGMEDIASIZE");

        /*
         * Check if that partition is suitable for growing a file system.
         */
        if (mediasize < 1)
                errx(2, "partition is unavailable");

        /*
         * Read the current superblock, and take a backup.
         */
        if ((ret = sbget(fsi, &fs, UFS_STDSB, 0)) != 0) {
                switch (ret) {
                case ENOENT:
                        errx(2, "superblock not recognized");
                default:
                        errc(3, ret, "unable to read superblock");
                }
        }
        /*
         * Check for filesystem that was unclean at mount time.
         */
        if ((fs->fs_flags & (FS_UNCLEAN | FS_NEEDSFSCK)) != 0)
                errx(2, "%s is not clean - run fsck.\n", *argv);
        memcpy(&osblock, fs, fs->fs_sbsize);
        free(fs);
        memcpy((void *)&fsun1, (void *)&fsun2, osblock.fs_sbsize);

        DBG_OPEN("/tmp/growfs.debug"); /* already here we need a superblock */
        DBG_DUMP_FS(&sblock, "old sblock");

        /*
         * Determine size to grow to. Default to the device size.
         */
        if (size == 0)
                size = mediasize;
        else {
                if (size > (uint64_t)mediasize) {
                        humanize_number(oldsizebuf, sizeof(oldsizebuf), size,
                            "B", HN_AUTOSCALE, HN_B | HN_NOSPACE | HN_DECIMAL);
                        humanize_number(newsizebuf, sizeof(newsizebuf),
                            mediasize,
                            "B", HN_AUTOSCALE, HN_B | HN_NOSPACE | HN_DECIMAL);

                        errx(2, "requested size %s is larger "
                            "than the available %s", oldsizebuf, newsizebuf);
                }
        }

        /*
         * Make sure the new size is a multiple of fs_fsize; /dev/ufssuspend
         * only supports fragment-aligned IO requests.
         */
        size -= size % osblock.fs_fsize;

        if (size <= (uint64_t)(osblock.fs_size * osblock.fs_fsize)) {
                humanize_number(oldsizebuf, sizeof(oldsizebuf),
                    osblock.fs_size * osblock.fs_fsize,
                    "B", HN_AUTOSCALE, HN_B | HN_NOSPACE | HN_DECIMAL);
                humanize_number(newsizebuf, sizeof(newsizebuf), size,
                    "B", HN_AUTOSCALE, HN_B | HN_NOSPACE | HN_DECIMAL);

                if (size == (uint64_t)(osblock.fs_size * osblock.fs_fsize))
                        errx(0, "requested size %s is equal to the current "
                            "filesystem size %s", newsizebuf, oldsizebuf);
                errx(2, "requested size %s is smaller than the current "
                   "filesystem size %s", newsizebuf, oldsizebuf);
        }

        sblock.fs_old_size = sblock.fs_size =
            dbtofsb(&osblock, size / DEV_BSIZE);
        sblock.fs_providersize = dbtofsb(&osblock, mediasize / DEV_BSIZE);

        /*
         * Are we really growing?
         */
        if (osblock.fs_size >= sblock.fs_size) {
                errx(3, "we are not growing (%jd->%jd)",
                    (intmax_t)osblock.fs_size, (intmax_t)sblock.fs_size);
        }

        /*
         * Check if we find an active snapshot.
         */
        if (yflag == 0) {
                for (j = 0; j < FSMAXSNAP; j++) {
                        if (sblock.fs_snapinum[j]) {
                                errx(2, "active snapshot found in file system; "
                                    "please remove all snapshots before "
                                    "using growfs");
                        }
                        if (!sblock.fs_snapinum[j]) /* list is dense */
                                break;
                }
        }

        if (yflag == 0 && Nflag == 0) {
                if (statfsp != NULL && (statfsp->f_flags & MNT_RDONLY) == 0)
                        printf("Device is mounted read-write; resizing will "
                            "result in temporary write suspension for %s.\n",
                            statfsp->f_mntonname);
                printf("It's strongly recommended to make a backup "
                    "before growing the file system.\n"
                    "OK to grow filesystem on %s", device);
                if (statfsp != NULL)
                        printf(", mounted on %s,", statfsp->f_mntonname);
                humanize_number(oldsizebuf, sizeof(oldsizebuf),
                    osblock.fs_size * osblock.fs_fsize,
                    "B", HN_AUTOSCALE, HN_B | HN_NOSPACE | HN_DECIMAL);
                humanize_number(newsizebuf, sizeof(newsizebuf),
                    sblock.fs_size * sblock.fs_fsize,
                    "B", HN_AUTOSCALE, HN_B | HN_NOSPACE | HN_DECIMAL);
                printf(" from %s to %s? [yes/no] ", oldsizebuf, newsizebuf);
                fflush(stdout);
                fgets(reply, (int)sizeof(reply), stdin);
                if (strcasecmp(reply, "yes\n")){
                        printf("Response other than \"yes\"; aborting\n");
                        exit(0);
                }
        }

        /*
         * Try to access our device for writing.  If it's not mounted,
         * or mounted read-only, simply open it; otherwise, use UFS
         * suspension mechanism.
         */
        if (Nflag) {
                fso = -1;
        } else {
                if (statfsp != NULL && (statfsp->f_flags & MNT_RDONLY) == 0) {
                        fso = open(_PATH_UFSSUSPEND, O_RDWR);
                        if (fso == -1)
                                err(3, "unable to open %s", _PATH_UFSSUSPEND);
                        error = ioctl(fso, UFSSUSPEND, &statfsp->f_fsid);
                        if (error != 0)
                                err(3, "UFSSUSPEND");
                } else {
                        fso = open(device, O_WRONLY);
                        if (fso < 0)
                                err(3, "%s", device);
                }
        }

        /*
         * Try to access our new last block in the file system.
         */
        testbuf = malloc(sblock.fs_fsize);
        if (testbuf == NULL)
                err(3, "malloc");
        rdfs((ufs2_daddr_t)((size - sblock.fs_fsize) / DEV_BSIZE),
            sblock.fs_fsize, testbuf, fsi);
        wtfs((ufs2_daddr_t)((size - sblock.fs_fsize) / DEV_BSIZE),
            sblock.fs_fsize, testbuf, fso, Nflag);
        free(testbuf);

        /*
         * Now calculate new superblock values and check for reasonable
         * bound for new file system size:
         *     fs_size:    is derived from user input
         *     fs_dsize:   should get updated in the routines creating or
         *                 updating the cylinder groups on the fly
         *     fs_cstotal: should get updated in the routines creating or
         *                 updating the cylinder groups
         */

        /*
         * Update the number of cylinders and cylinder groups in the file system.
         */
        if (sblock.fs_magic == FS_UFS1_MAGIC) {
                sblock.fs_old_ncyl =
                    sblock.fs_size * sblock.fs_old_nspf / sblock.fs_old_spc;
                if (sblock.fs_size * sblock.fs_old_nspf >
                    sblock.fs_old_ncyl * sblock.fs_old_spc)
                        sblock.fs_old_ncyl++;
        }
        sblock.fs_ncg = howmany(sblock.fs_size, sblock.fs_fpg);

        /*
         * Allocate last cylinder group only if there is enough room
         * for at least one data block.
         */
        if (sblock.fs_size % sblock.fs_fpg != 0 &&
            sblock.fs_size <= cgdmin(&sblock, sblock.fs_ncg - 1)) {
                humanize_number(oldsizebuf, sizeof(oldsizebuf),
                    (sblock.fs_size % sblock.fs_fpg) * sblock.fs_fsize,
                    "B", HN_AUTOSCALE, HN_B | HN_NOSPACE | HN_DECIMAL);
                warnx("no room to allocate last cylinder group; "
                    "leaving %s unused", oldsizebuf);
                sblock.fs_ncg--;
                if (sblock.fs_magic == FS_UFS1_MAGIC)
                        sblock.fs_old_ncyl = sblock.fs_ncg * sblock.fs_old_cpg;
                sblock.fs_old_size = sblock.fs_size =
                    sblock.fs_ncg * sblock.fs_fpg;
        }

        /*
         * Update the space for the cylinder group summary information in the
         * respective cylinder group data area.
         */
        sblock.fs_cssize =
            fragroundup(&sblock, sblock.fs_ncg * sizeof(struct csum));

        if (osblock.fs_size >= sblock.fs_size)
                errx(3, "not enough new space");

        DBG_PRINT0("sblock calculated\n");

        /*
         * Ok, everything prepared, so now let's do the tricks.
         */
        growfs(fsi, fso, Nflag);

        close(fsi);
        if (fso > -1) {
                if (statfsp != NULL && (statfsp->f_flags & MNT_RDONLY) == 0) {
                        error = ioctl(fso, UFSRESUME);
                        if (error != 0)
                                err(3, "UFSRESUME");
                }
                error = close(fso);
                if (error != 0)
                        err(3, "close");
                if (statfsp != NULL && (statfsp->f_flags & MNT_RDONLY) != 0 &&
                    chkdoreload(statfsp, warn) != 0)
                        exit(9);
        }

        DBG_CLOSE;

        DBG_LEAVE;
        return (0);
}

/*
 * Dump a line of usage.
 */
static void
usage(void)
{
        DBG_FUNC("usage")

        DBG_ENTER;

        fprintf(stderr, "usage: growfs [-Ny] [-s size] special | filesystem\n");

        DBG_LEAVE;
        exit(1);
}

/*
 * This updates most parameters and the bitmap related to cluster. We have to
 * assume that sblock, osblock, acg are set up.
 */
static void
updclst(int block)
{
        DBG_FUNC("updclst")
        static int lcs = 0;

        DBG_ENTER;

        if (sblock.fs_contigsumsize < 1) /* no clustering */
                return;
        /*
         * update cluster allocation map
         */
        setbit(cg_clustersfree(&acg), block);

        /*
         * update cluster summary table
         */
        if (!lcs) {
                /*
                 * calculate size for the trailing cluster
                 */
                for (block--; lcs < sblock.fs_contigsumsize; block--, lcs++ ) {
                        if (isclr(cg_clustersfree(&acg), block))
                                break;
                }
        }
        if (lcs < sblock.fs_contigsumsize) {
                if (lcs)
                        cg_clustersum(&acg)[lcs]--;
                lcs++;
                cg_clustersum(&acg)[lcs]++;
        }

        DBG_LEAVE;
        return;
}

/*
 * Calculate the check-hash of the cylinder group.
 */
static void
cgckhash(struct cg *cgp)
{

        if ((sblock.fs_metackhash & CK_CYLGRP) == 0)
                return;
        cgp->cg_ckhash = 0;
        cgp->cg_ckhash = calculate_crc32c(~0L, (void *)cgp, sblock.fs_cgsize);
}